70 resultados para INFRARED FUNDAMENTAL INTENSITIES


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The ideal therapy for early stages of hemorrhoids is always debated. Some are more effective but are more painful, others are less painful but their efficacy is also lower. Thus, comfort or efficacy is a major concern. In the present randomized study, a comparison is made between infrared coagulation and rubber band ligation in terms of effectiveness and discomfort. One hundred patients with second degree bleeding piles were randomized prospectively to either rubber band ligation (N = 54) or infrared coagulation (N = 46). Parameters measured included postoperative discomfort and pain, time to return to work, relief in incidence of bleeding, and recurrence rate. The mean age was 38 years (range 19-68 years). The mean duration of disease was 17.5 months (range 12 to 34 months). The number of male patients was double that of females. Postoperative pain during the first week was more intense in the band ligation group (2-5 vs 0-3 on a visual analogue scale). Post-defecation pain was more intense with band ligation and so was rectal tenesmus (P = 0.0059). The patients in the infrared coagulation group resumed their duties earlier (2 vs 4 days, P = 0.03), but also had a higher recurrence or failure rate (P = 0.03). Thus, we conclude that band ligation, although more effective in controlling symptoms and obliterating hemorrhoids, is associated with more pain and discomfort to the patient. As infrared coagulation can be conveniently repeated in case of recurrence, it could be considered to be a suitable alternative office procedure for the treatment of early stage hemorrhoids.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The pressure sensitivities of the near infrared spectra of the light-harvesting (LH2) complex and a mutant complex with a simplified BChl-B850 binding pocket were compared. In the mutant an abrupt change in the spectral properties occurred at 250 MPa, which was not observed with the native sample. Increased disorder due to collapse of the chromophore pocket is suggested.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study examined the effects of pre-exercise carbohydrate availability on the time to exhaustion for moderate and heavy exercise. Seven men participated in a randomized order in two diet and exercise regimens each lasting 3 days with a 1-week interval for washout. The tests were performed at 50% of the difference between the first (LT1) and second (LT2) lactate breakpoint for moderate exercise (below LT2) and at 25% of the difference between the maximal load and LT2 for heavy exercise (above LT2) until exhaustion. Forty-eight hours before each experimental session, subjects performed a 90-min cycling exercise followed by 5-min rest periods and a subsequent 1-min cycling bout at 125% VO2max/1-min rest periods until exhaustion to deplete muscle glycogen. A diet providing 10% (CHOlow) or 65% (CHOmod) energy as carbohydrates was consumed for 2 days until the day of the experimental test. In the exercise below LT2, time to exhaustion did not differ between the CHOmod and the CHOlow diets (57.22 ± 24.24 vs 57.16 ± 25.24 min). In the exercise above LT2, time to exhaustion decreased significantly from 23.16 ± 8.76 min on the CHOmod diet to 18.30 ± 5.86 min on the CHOlow diet (P < 0.05). The rate of carbohydrate oxidation, respiratory exchange ratio and blood lactate concentration were reduced for CHOlow only during exercise above LT2. These results suggest that muscle glycogen depletion followed by a period of a low carbohydrate diet impairs high-intensity exercise performance.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

There is evidence that brain temperature (Tbrain) provides a more sensitive index than other core body temperatures in determining physical performance. However, no study has addressed whether the association between performance and increases in Tbrain in a temperate environment is dependent upon exercise intensity, and this was the primary aim of the present study. Adult male Wistar rats were subjected to constant exercise at three different speeds (18, 21, and 24 m/min) until the onset of volitional fatigue. Tbrain was continuously measured by a thermistor inserted through a brain guide cannula. Exercise induced a speed-dependent increase in Tbrain, with the fastest speed associated with a higher rate of Tbrain increase. Rats subjected to constant exercise had similar Tbrain values at the time of fatigue, although a pronounced individual variability was observed (38.7-41.7°C). There were negative correlations between the rate of Tbrain increase and performance for all speeds that were studied. These results indicate that performance during constant exercise is negatively associated with the increase in Tbrain, particularly with its rate of increase. We then investigated how an incremental-speed protocol affected the association between the increase in Tbrain and performance. At volitional fatigue, Tbrain was lower during incremental exercise compared with the Tbrain resulting from constant exercise (39.3±0.3 vs 40.3±0.1°C; P<0.05), and no association between the rate of Tbrain increase and performance was observed. These findings suggest that the influence of Tbrain on performance under temperate conditions is dependent on exercise protocol.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Low-intensity lasers are used for prevention and management of oral mucositis induced by anticancer therapy, but the effectiveness of treatment depends on the genetic characteristics of affected cells. This study evaluated the survival and induction of filamentation of Escherichia coli cells deficient in the nucleotide excision repair pathway, and the action of T4endonuclease V on plasmid DNA exposed to low-intensity red and near-infrared laser light. Cultures of wild-type (strain AB1157) E. coli and strain AB1886 (deficient in uvrA protein) were exposed to red (660 nm) and infrared (808 nm) lasers at various fluences, powers and emission modes to study bacterial survival and filamentation. Also, plasmid DNA was exposed to laser light to study DNA lesions produced in vitro by T4endonuclease V. Low-intensity lasers:i) had no effect on survival of wild-type E. coli but decreased the survival of uvrA protein-deficient cells,ii) induced bacterial filamentation, iii) did not alter the electrophoretic profile of plasmids in agarose gels, andiv) did not alter the electrophoretic profile of plasmids incubated with T4 endonuclease V. These results increase our understanding of the effects of laser light on cells with various genetic characteristics, such as xeroderma pigmentosum cells deficient in nucleotide excision pathway activity in patients with mucositis treated by low-intensity lasers.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Semiconductor laser devices are readily available and practical radiation sources providing wavelength tenability and high monochromaticity. Low-intensity red and near-infrared lasers are considered safe for use in clinical applications. However, adverse effects can occur via free radical generation, and the biological effects of these lasers from unusually high fluences or high doses have not yet been evaluated. Here, we evaluated the survival, filamentation induction and morphology of Escherichia coli cells deficient in repair of oxidative DNA lesions when exposed to low-intensity red and infrared lasers at unusually high fluences. Cultures of wild-type (AB1157), endonuclease III-deficient (JW1625-1), and endonuclease IV-deficient (JW2146-1) E. coli, in exponential and stationary growth phases, were exposed to red and infrared lasers (0, 250, 500, and 1000 J/cm2) to evaluate their survival rates, filamentation phenotype induction and cell morphologies. The results showed that low-intensity red and infrared lasers at high fluences are lethal, induce a filamentation phenotype, and alter the morphology of the E. coli cells. Low-intensity red and infrared lasers have potential to induce adverse effects on cells, whether used at unusually high fluences, or at high doses. Hence, there is a need to reinforce the importance of accurate dosimetry in therapeutic protocols.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The objective of this work was to determine and model the infrared dehydration curves of apple slices - Fuji and Gala varieties. The slices were dehydrated until constant mass, in a prototype dryer with infrared heating source. The applied temperatures ranged from 50 to 100 °C. Due to the physical characteristics of the product, the dehydration curve was divided in two periods, constant and falling, separated by the critical moisture content. A linear model was used to describe the constant dehydration period. Empirical models traditionally used to model the drying behavior of agricultural products were fitted to the experimental data of the falling dehydration period. Critical moisture contents of 2.811 and 3.103 kgw kgs-1 were observed for the Fuji and Gala varieties, respectively. Based on the results, it was concluded that the constant dehydration rates presented a direct relationship with the temperature; thus, it was possible to fit a model that describes the moisture content variation in function of time and temperature. Among the tested models, which describe the falling dehydration period, the model proposed by Midilli presented the best fit for all studied conditions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Celso Furtado, the return to the basic controversy. A reading of the work of Celso Furtado in its completion opens an enriching view of the interaction between theoretical thinking and the unveiling of Latin-America history. Starting from an appraisal of the pre-Classic and Classic authors, Furtado outlined an approach of surplus theory. That would enable development theory to deal with the unevenly industrialized economies like Brazil. His thorough analysis of development and underdevelopment processes broke away from the initial ECLA experiences to build a planning proposal the uprising country. The French roots of his academic profile helped him to keep an orderly explanation of capital demand that kept him siding with Wicksell against the subjective theory of Schumpeter.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Quality of municipal public spending on primary education in Brazil. The focus of this paper was to analyze the relationship between municipal public education spending and students' academic achievement, evaluated according to IDEB (Index of Basic Education Development) of 2005. The following databases were used: School Census 2005, Brazil Exam (mathematics evaluation applied to students from fourth grade of elementary school) and Finance of Brazil (FINBRA). A multilevel model was estimated and the results suggest that simply increasing the percentage of municipal expenditures on education or the percentage of spending on primary education in relation to municipal expenditures on education do not automatically guarantee improvements in the quality of education.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

O principal ponto de desacordo sobre a abordagem kantiana do problema da verdade é se ela pode ser compreendida nos moldes da filosofia contemporânea como coerentista ou como correspondentista. Primando por uma consideração sistemática da argumentação de Kant em confronto com a literatura existente sobre o problema, este trabalho defende a segunda alternativa. Sustenta-se a tese de que a definição da verdade como a "concordância do conhecimento com o seu objeto" é cogente em todo o percurso do pensamento kantiano e que, nessa acepção, a verdade culmina por ser abordada não a partir de uma teoria estabelecida, mas como um problema cuja solução não pode ser dada nos limites da filosofia crítico-transcendental. Pondera-se, primeiramente, a literatura que situa Kant quer como coerentista quer como correspondentista e sistematiza-se a segunda alternativa em quatro grupos: a leitura ontológica, a leitura isomórfica, a leitura "consequencialista" e a leitura regulativa. Num segundo momento, em atenção ao período pré-crítico, argumenta-se que a alternativa coerentista deixa de se confirmar já nessa mesma época e que, na década de 1750, Kant descarta uma suposta teoria correspondentista isomórfica. Num último momento, considera-se a argumentação crítica e defende-se que a mesma concebe a verdade como um problema fundamental que não cabe ao tratamento de uma teoria correspondentista concebida de modo "consequencialista" ou regulativo.